Sodium Electron Configuration
Sodium (Na) · 11 electrons · Alkali metal
1s2 2s2 2p6 3s1
Noble gas notation: [Ne] 3s1
Orbital diagram
↑↓
1s↑↓
2s↑↓↑↓↑↓
2p↑
3s- Valence electrons
- 1
- Unpaired electrons
- 1
- Block
- s-block
- Magnetism (atom)
- paramagnetic
Electrons per shell
| K (n = 1) | 2 |
|---|---|
| L (n = 2) | 8 |
| M (n = 3) | 1 |
Sodium ion configurations
| Ion | Electrons | Configuration |
|---|---|---|
| Na+ | 10 | [He] 2s2 2p6 |
How to write it
Place 11 electrons into subshells in the Aufbau order (1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p), filling s with 2, p with 6, d with 10 and f with 14. Sodium sits in period 3, group 1, in the s-block, so its last electron enters an s subshell. Replacing the inner electrons with the previous noble gas gives the shorthand [Ne] 3s1.
Try sodium and its ions in the calculator, or see the full sodium data sheet.
Sodium electron configuration FAQ
What is the electron configuration of sodium?
1s² 2s² 2p⁶ 3s¹. Shorthand (noble gas) notation: [Ne] 3s¹.
What is the noble gas configuration of sodium?
[Ne] 3s¹. The bracket stands for the Ne core electrons.
How many valence electrons does sodium have?
1 (outer shell (n = 3)).
How many unpaired electrons does sodium have?
1 in the ground state, following Hund’s rule. An atom with unpaired electrons is paramagnetic.
What is the electron configuration of Na+?
[He] 2s² 2p⁶ (10 electrons).